The while statement creates a loop that evaluates a expression
to see if it is true or false, and if true, executes
a block of statements and then repeats the loop, or if false, immediately
exits the loop.

The while statement will iterate the loop as long as the specified
expression remains true. Therefore, if the expression never tests
false, the loop will continue forever in what is called an "infinite
loop."

The block of statements executed by the while statement can be
any legal WMLS code (including more while statements).